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US4025674A - Reflex light reflecting sheet - Google Patents

Reflex light reflecting sheet Download PDF

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Publication number
US4025674A
US4025674A US05/612,693 US61269375A US4025674A US 4025674 A US4025674 A US 4025674A US 61269375 A US61269375 A US 61269375A US 4025674 A US4025674 A US 4025674A
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United States
Prior art keywords
reflecting sheet
light reflecting
layer
transparent
coating layer
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Expired - Lifetime
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US05/612,693
Inventor
Hisayuki Mizuochi
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Seibu Polymer Kasei KK
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Seibu Polymer Kasei KK
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
    • B32B3/02—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions
    • B32B3/08—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by added members at particular parts
    • B32B3/085—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by added members at particular parts spaced apart pieces on the surface of a layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/12—Reflex reflectors
    • G02B5/126—Reflex reflectors including curved refracting surface
    • G02B5/128—Reflex reflectors including curved refracting surface transparent spheres being embedded in matrix
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/308—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising acrylic (co)polymers
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F13/00—Illuminated signs; Luminous advertising
    • G09F13/16—Signs formed of or incorporating reflecting elements or surfaces, e.g. warning signs having triangular or other geometrical shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00—Coating on the layer surface
    • B32B2255/20—Inorganic coating
    • B32B2255/205—Metallic coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/416—Reflective
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2551/00—Optical elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
    • Y10T428/24851—Intermediate layer is discontinuous or differential
    • Y10T428/24868—Translucent outer layer
    • Y10T428/24876—Intermediate layer contains particulate material [e.g., pigment, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
    • Y10T428/24926—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including ceramic, glass, porcelain or quartz layer
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • Y10T428/252—Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]

Definitions

  • This invention relates to a reflex light reflecting sheet, and more particularly to a reflex light reflecting sheet having a printed portion, the printed portion being visible under scattered light in the daytime but invisible in the nighttime.
  • the printed portion for reflecting the incident light is provided behind the small transparent balls in the reflecting sheet. Therefore, when high-brightness reflection is required, it is necessary to form print on the mirror surfaces concentric with the small transparent balls. In other words, it is necessary to apply uniform printing on a plurality of concave mirror surfaces. It is, however, extremely difficult to accomplish this on such surface portions which do not lie on the same plane. Thus, a certain decline in brightness has been considered inevitable in conventional reflex light reflecting sheet.
  • the present invention has solved these problems of the prior art, and has as its object to provide a novel reflex light reflecting sheet having a printed portion or print which is readily and distinctly visible under scattered light in the daytime but invisible under reflected light in the nighttime, and wherein the printing of said printed portion can be accomplished with ease.
  • Another object of the present invention is to devise a reflex light reflecting sheet of the type described, wherein a printed portion is provided in a transparent layer which constitutes the surface coating layer of the reflecting sheet.
  • Still another object of the present invention is to provide a reflex light reflecting sheet of the type described wherein said surface coating layer is composed of two sub-layers and a printed portion is positioned between said two sub-layers.
  • Yet another object of the present invention is to provide a reflex light reflecting sheet of the said type wherein the printed portion formed in said surface coating layer is formed by lines having a thickness of less than 0.5 mm.
  • FIG. 1 is a longitudinal sectional view showing a prior art reflex light reflecting sheet
  • FIG. 2 is a longitudinal sectional view showing a reflex light reflecting sheet according to the present invention.
  • FIGS. 3 and 4 are diagrammatic drawings showing how light is reflected when the reflecting sheet receives scattered light in the daytime and reflected light in the nighttime respectively.
  • a printed layer 12 is provided on one side of the reflective layer 11, and a spacing layer 13, a binder layer 14 having embedded therein a plurality of small transparent balls 15, and a surface coating layer 16 are laminated in that order on said printed layer 12.
  • the printed layer 12 is composed of particles of a material which allows semi-mirror-reflection
  • the reflecting layer 11 is composed of a material which allows mirror-reflection
  • none of the part of the width of the printed layer 12 exceeds about 1/64th of an inch
  • further said printed layer 12 is such that its reflective strength in the visible spectrum is 40 to 90% of the total mirror-surface reflection strength shown by the reflecting layer 11 in the visible spectrum, and thereby the printed layer 12 is visible under scattered light in the daytime when viewed from the front of the reflecting sheet through the naked eye but invisible under the reflected light.
  • the internal light reflective layer must be formed as a mirror surface which is concentric with the small transparent balls 15 embedded in front of said layer. Accordingly, in conventional reflex light reflecting sheet, it is required that the printed layer be formed on the mirror surfaces concentric with the small transparent balls or that the printing must be effected uniformly on a plurality of concave mirror surfaces, however, it is extremely difficult to accomplish this uniform printing on the concave mirror surfaces.
  • the reflex light reflecting sheet 6 comprises a laminated layer consisting of a surface coating layer 5 which is transparent and flat, a transparent binder layer 3 at the rear of the said surface coating layer 5, a ball-arranged layer 4 consisting of a plurality of small transparent balls 4A which is partly embedded in said binder layer 3, a transparent spacing layer 2 covering the remaining portions of said ball-arranged layer 4, and a reflective layer 1 at the rear of the spacing layer 2, in that order, the said surface coating layer 5 being composed of two sub-layers 5A, 5B, between the interfacial boundary of which a printed layer 7 is provided. It is desirable to have the small transparent balls 4A half embedded in the binder layer 3.
  • the focal point of the small transparent balls 4A is so arranged as to be on the reflective layer 1, and that the spacing layer 2 is provided so as to have the reflective layer 1 at the rear of the layer 2 formed concentrically with the small transparent balls 4A.
  • Both the two layers 5A, 5B constituting the surface coating layer 5 in said reflex light reflecting sheet 6 are formed from transparent thermosetting resin having a refractive index of 1.52, and a weight per unit area of 20 to 23 g/m 2 .
  • the printed layer 7 has a refractive index of 1.52 and is printed with lines less than 0.3 mm in transparent or semitransparent ink by using a printing process such as photogravure printing on one of the two sub-layers 5A or 5B of the surface coating layer 5.
  • the binder layer 3 is also made of transparent thermosetting acrylic resin having a weight per unit area of 25 to 28 g/m 2 .
  • Each of the small transparent balls 4A is a transparent shperical body with a refractive index of 2.2 and a grain size of 60 to 90 ⁇ .
  • the spacing layer 2 is formed from transparent thermosetting acrylic resin having a refractive index of 1.52 and a weight per unit area of 30 to 35 g/m 2 .
  • the reflective layer 1 is formed by the deposition of metal such as aluminum having a thickness of 200 A and is integral with the spacing layer 2.
  • the printed layer 7 becomes invisible when the reflecting sheet receives reflected light in the nighttime because strong reflected light rays suppress reflections from the printed layer 7 due to the diffraction of light.
  • the width of the lines in the printed layer 7 is greater than a certain value, that part of the light irradiated area which is covered by the printed layer 7 becomes larger than the other part, and hence even when strong reflected light is present, the printed layer 7 can no longer be completely obscured by the diffracted light, so that the printed layer 7 becomes visible from the outside.
  • the width of the lines in the printed portion used in the present invention must be less than 0.5 mm.
  • the printed layer 7 may have from half to complete transparency, it is desirable to maintain transmittance of the printed layer 7 at 70 to 100% of that of other layers. If the transmittance of the printed layer 7 is less than 70% of that of other layers, the light rays transmitted through the printed layer 7 in the nighttime are so reduced that they are unable to completely obscure the printed lines in said portion, even with the aid of diffraction of the reflex reflected light rays that pass through the other layers, and consequently the incompletely obscured portion becomes visible as "shade" and brightness of reflection is lowered, making it impossible to accomplish the object of the present invention.
  • the printing ink and pigment used for printing in the printed layer 7 can range widely in particle size from less than 1 ⁇ to about 40 ⁇ , this particle size must be selected properly according to the color of the reflex light reflecting sheet. If the particle size of pigment is too large, this results in a reduction in transmittance, making it difficult to obscure the letters or such in the printed layer 7 even under reflected light in the nighttime. Thus, there is a certain limitation on the particle size of pigment used in the present invention.
  • thermosetting resin such as alkyd resin or acrylic resin for one of the coating layers 5A or 5B.
  • the printed layer 7 can be provided at any location within the range spanning from the rear to the front of the surface coating layer 5, but it is necessary to select this location according to the thickness of the ink used or the size of the printed lines. Also, if the distance from the small transparent balls 4A to the printed layer 7 is too great, the light rays which have passed the printed layer 7 may be diffused and become hardly perceptible. And furthermore, in case the width of the printed line is narrow, the printed layer 7 becomes invisible under the reflex reflected light ray from the outside and therefore, the reflex reflected light ray can be uniformly visible.
  • FIG. 3 shows a situation where the printed layer 7 is visible owing to irregular reflection of light L1 when scattered light impinges thereon in the daytime
  • FIG. 4 shows a situation where the printed surface is invisible from the outside when viewed under reflected light L2 in the nighttime.
  • a portion printed with lines less than 0.5 mm in size is provided in the surface coating layer 5 so that such printed layer 7 will be distinctly visible in scattered light in the daytime but invisible in reflected light in the nighttime, thus allowing very easy discernment.
  • the present invention since it is merely required to do the printing in the surface coating layer 5, such printing can be accomplished with ease, and also, since such printing is done between layers, it is possible to reduce the thickness of the printed layer, thus eliminating any possibility of reducing brightness even when the reflex light reflecting sheet is of high-brightness type.
  • the device according to the present invention is easy to manufacture and has many advantages that can never be obtained with conventional devices.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Geometry (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Illuminated Signs And Luminous Advertising (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Laminated Bodies (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

A reflex light reflecting sheet or reflective structure whereby incident light is reflected from a reflective layer on the rear of the structure through a plurality of small transparent balls, wherein a surface coating layer which is transparent and flat is formed over the surfaces of said balls, said layer being composed of two sub-layers between which is provided a printed portion using fine lines for printing, such that the printed portion is visible in scattered light in the daytime but invisible in reflected light in the nighttime.

Description

BACKGROUND OF THE INVENTION
This invention relates to a reflex light reflecting sheet, and more particularly to a reflex light reflecting sheet having a printed portion, the printed portion being visible under scattered light in the daytime but invisible in the nighttime.
BRIEF DESCRIPTION OF THE PRIOR ART
In currently used reflex light reflecting sheet, the printed portion for reflecting the incident light is provided behind the small transparent balls in the reflecting sheet. Therefore, when high-brightness reflection is required, it is necessary to form print on the mirror surfaces concentric with the small transparent balls. In other words, it is necessary to apply uniform printing on a plurality of concave mirror surfaces. It is, however, extremely difficult to accomplish this on such surface portions which do not lie on the same plane. Thus, a certain decline in brightness has been considered inevitable in conventional reflex light reflecting sheet.
SUMMARY OF THE INVENTION
The present invention has solved these problems of the prior art, and has as its object to provide a novel reflex light reflecting sheet having a printed portion or print which is readily and distinctly visible under scattered light in the daytime but invisible under reflected light in the nighttime, and wherein the printing of said printed portion can be accomplished with ease.
Another object of the present invention is to devise a reflex light reflecting sheet of the type described, wherein a printed portion is provided in a transparent layer which constitutes the surface coating layer of the reflecting sheet.
Still another object of the present invention is to provide a reflex light reflecting sheet of the type described wherein said surface coating layer is composed of two sub-layers and a printed portion is positioned between said two sub-layers.
Yet another object of the present invention is to provide a reflex light reflecting sheet of the said type wherein the printed portion formed in said surface coating layer is formed by lines having a thickness of less than 0.5 mm.
The other objects and advantages of the present invention will become apparent as this invention is more fully described hereinafter, with reference to the accompanying drawings, in which:
FIG. 1 is a longitudinal sectional view showing a prior art reflex light reflecting sheet;
FIG. 2 is a longitudinal sectional view showing a reflex light reflecting sheet according to the present invention; and
FIGS. 3 and 4 are diagrammatic drawings showing how light is reflected when the reflecting sheet receives scattered light in the daytime and reflected light in the nighttime respectively.
DETAILED DESCRIPTION OF THE INVENTION
In currently used reflex light reflecting sheet, as exemplified in FIG. 1, a printed layer 12 is provided on one side of the reflective layer 11, and a spacing layer 13, a binder layer 14 having embedded therein a plurality of small transparent balls 15, and a surface coating layer 16 are laminated in that order on said printed layer 12. In this reflex light reflecting sheet, the printed layer 12 is composed of particles of a material which allows semi-mirror-reflection, the reflecting layer 11 is composed of a material which allows mirror-reflection, none of the part of the width of the printed layer 12 exceeds about 1/64th of an inch, further said printed layer 12 is such that its reflective strength in the visible spectrum is 40 to 90% of the total mirror-surface reflection strength shown by the reflecting layer 11 in the visible spectrum, and thereby the printed layer 12 is visible under scattered light in the daytime when viewed from the front of the reflecting sheet through the naked eye but invisible under the reflected light.
However, when a reflex light reflecting sheet with high brightness is required, the internal light reflective layer must be formed as a mirror surface which is concentric with the small transparent balls 15 embedded in front of said layer. Accordingly, in conventional reflex light reflecting sheet, it is required that the printed layer be formed on the mirror surfaces concentric with the small transparent balls or that the printing must be effected uniformly on a plurality of concave mirror surfaces, however, it is extremely difficult to accomplish this uniform printing on the concave mirror surfaces.
Now, a preferred embodiment of the present invention will be described with reference to the figures.
In FIG. 2, the reflex light reflecting sheet 6 comprises a laminated layer consisting of a surface coating layer 5 which is transparent and flat, a transparent binder layer 3 at the rear of the said surface coating layer 5, a ball-arranged layer 4 consisting of a plurality of small transparent balls 4A which is partly embedded in said binder layer 3, a transparent spacing layer 2 covering the remaining portions of said ball-arranged layer 4, and a reflective layer 1 at the rear of the spacing layer 2, in that order, the said surface coating layer 5 being composed of two sub-layers 5A, 5B, between the interfacial boundary of which a printed layer 7 is provided. It is desirable to have the small transparent balls 4A half embedded in the binder layer 3. In order to prevent the lowering of the brightness of the reflected light, it is also desirable that the focal point of the small transparent balls 4A is so arranged as to be on the reflective layer 1, and that the spacing layer 2 is provided so as to have the reflective layer 1 at the rear of the layer 2 formed concentrically with the small transparent balls 4A. Both the two layers 5A, 5B constituting the surface coating layer 5 in said reflex light reflecting sheet 6 are formed from transparent thermosetting resin having a refractive index of 1.52, and a weight per unit area of 20 to 23 g/m2. The printed layer 7 has a refractive index of 1.52 and is printed with lines less than 0.3 mm in transparent or semitransparent ink by using a printing process such as photogravure printing on one of the two sub-layers 5A or 5B of the surface coating layer 5. The binder layer 3 is also made of transparent thermosetting acrylic resin having a weight per unit area of 25 to 28 g/m2.
Each of the small transparent balls 4A is a transparent shperical body with a refractive index of 2.2 and a grain size of 60 to 90μ. The spacing layer 2 is formed from transparent thermosetting acrylic resin having a refractive index of 1.52 and a weight per unit area of 30 to 35 g/m2. The reflective layer 1 is formed by the deposition of metal such as aluminum having a thickness of 200 A and is integral with the spacing layer 2.
In this embodiment, the printed layer 7 becomes invisible when the reflecting sheet receives reflected light in the nighttime because strong reflected light rays suppress reflections from the printed layer 7 due to the diffraction of light. However, if the width of the lines in the printed layer 7 is greater than a certain value, that part of the light irradiated area which is covered by the printed layer 7 becomes larger than the other part, and hence even when strong reflected light is present, the printed layer 7 can no longer be completely obscured by the diffracted light, so that the printed layer 7 becomes visible from the outside.
Therefore, the width of the lines in the printed portion used in the present invention must be less than 0.5 mm. Although the printed layer 7 may have from half to complete transparency, it is desirable to maintain transmittance of the printed layer 7 at 70 to 100% of that of other layers. If the transmittance of the printed layer 7 is less than 70% of that of other layers, the light rays transmitted through the printed layer 7 in the nighttime are so reduced that they are unable to completely obscure the printed lines in said portion, even with the aid of diffraction of the reflex reflected light rays that pass through the other layers, and consequently the incompletely obscured portion becomes visible as "shade" and brightness of reflection is lowered, making it impossible to accomplish the object of the present invention.
Although the printing ink and pigment used for printing in the printed layer 7 can range widely in particle size from less than 1μ to about 40μ, this particle size must be selected properly according to the color of the reflex light reflecting sheet. If the particle size of pigment is too large, this results in a reduction in transmittance, making it difficult to obscure the letters or such in the printed layer 7 even under reflected light in the nighttime. Thus, there is a certain limitation on the particle size of pigment used in the present invention. In order to prevent the printed layer 7 from swelling during its formation, it is desirable to use thermosetting resin such as alkyd resin or acrylic resin for one of the coating layers 5A or 5B.
Assuming here that the thickness of the layer 5A is d1, the thickness of the layer 5B is d2 and the diameter of each small transparent ball 4A is D, and further assuming that the relationship of d1 + d2 = 1/2 D holds, then it was found desirable to set the relationship of d2 ≧ D/4 for certain types of printing ink. The printed layer 7 can be provided at any location within the range spanning from the rear to the front of the surface coating layer 5, but it is necessary to select this location according to the thickness of the ink used or the size of the printed lines. Also, if the distance from the small transparent balls 4A to the printed layer 7 is too great, the light rays which have passed the printed layer 7 may be diffused and become hardly perceptible. And furthermore, in case the width of the printed line is narrow, the printed layer 7 becomes invisible under the reflex reflected light ray from the outside and therefore, the reflex reflected light ray can be uniformly visible.
FIG. 3 shows a situation where the printed layer 7 is visible owing to irregular reflection of light L1 when scattered light impinges thereon in the daytime, and FIG. 4 shows a situation where the printed surface is invisible from the outside when viewed under reflected light L2 in the nighttime.
As described above, according to the reflex light reflecting sheet of the present invention, a portion printed with lines less than 0.5 mm in size is provided in the surface coating layer 5 so that such printed layer 7 will be distinctly visible in scattered light in the daytime but invisible in reflected light in the nighttime, thus allowing very easy discernment.
Further, according to the present invention, since it is merely required to do the printing in the surface coating layer 5, such printing can be accomplished with ease, and also, since such printing is done between layers, it is possible to reduce the thickness of the printed layer, thus eliminating any possibility of reducing brightness even when the reflex light reflecting sheet is of high-brightness type.
As is apparent from the foregoing description, the device according to the present invention is easy to manufacture and has many advantages that can never be obtained with conventional devices.

Claims (10)

What is claimed is:
1. A laminated reflex light reflecting sheet comprising in succession:
a flat, transparent surface coating layer,
a transparent binder layer at the rear of the coating layer,
a plurality of small transparent balls partially embedded in said transparent binder layer,
a transparent spacing layer covering the remaining portions of said balls, and
a reflective layer at the rear of said spacing layer,
said surface coating layer containing printing which is visible from the front of said surface coating layer in scattered daytime light, but substantially invisible in reflex reflected light at night, said printing consisting of lines less than 0.5 mm in size and having a transmittance at least 50% as great as the transmittance of said transparent layers.
2. The reflex light reflecting sheet set forth in claim 1, wherein said surface coating layer is composed of two sublayers and said printed portion is provided between said two sub-layers.
3. The reflex light reflecting sheet claimed in claim 2, wherein the two sub-layers constituting said surface coating layer are formed from transparent thermosetting resin having a refractive index of 1.52.
4. The reflex light reflecting sheet set forth in claim 1, wherein said printing is made of transparent or semitransparent ink having a refractive index of 1.52.
5. The reflex light reflecting sheet claimed in claim 2, wherein said printing is photogravured on one of the two sub-layers constituting said surface coating layer.
6. The reflex light reflecting sheet set forth in claim 1, wherein transmittance of said printing is 70 to 100% of the transmittance of the other layers.
7. The reflex light reflecting sheet claimed in claim 2, wherein a printing ink and pigment are used in said printing and have particle sizes ranging from less than 1μ to about 40μ.
8. The reflex light reflecting sheet claimed in claim 2, wherein the two sub-layers constituting said surface coating layer are formed from thermosetting resin.
9. The reflex light reflecting sheet claimed in claim 2, wherein the two sub-layers constituting said surface coating layer are different from each other in thickness.
10. The reflex light reflecting sheet set forth in claim 1, wherein said reflective layer is curved in conformity with the shape of said small transparent ball.
US05/612,693 1975-06-06 1975-09-12 Reflex light reflecting sheet Expired - Lifetime US4025674A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP50068203A JPS51144198A (en) 1975-06-06 1975-06-06 Return reflector
JA50-068203 1975-06-06

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US4025674A true US4025674A (en) 1977-05-24

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US (1) US4025674A (en)
JP (1) JPS51144198A (en)
AT (1) AT355460B (en)
BE (1) BE833604A (en)
DE (1) DE2542583C2 (en)
DK (1) DK152797C (en)
FR (1) FR2334123A1 (en)
GB (1) GB1470286A (en)
IT (1) IT1047575B (en)
LU (1) LU73425A1 (en)
NL (1) NL174405C (en)
SE (1) SE412960B (en)
ZA (1) ZA755962B (en)

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4264665A (en) * 1977-09-28 1981-04-28 Loefberg Hans F Reflex device with marking behind cover layer
US4405676A (en) * 1981-05-13 1983-09-20 Minnesota Mining & Manufacturing Company Decorative ribbon or sheet material
US4544586A (en) * 1982-12-27 1985-10-01 General Electric Company Laminar structure of polyester
US4609587A (en) * 1984-11-30 1986-09-02 Potters Industries, Inc. Retroreflective materials and use
US4639235A (en) * 1985-03-08 1987-01-27 Ibe Rebecca C Attachable eye for dolls
US4663213A (en) * 1985-11-18 1987-05-05 Minnesota Mining And Manufacturing Company Transparent multi-layer cover film for retroreflective sheeting
US4756931A (en) * 1984-11-30 1988-07-12 Potters Industries, Inc. Retroreflective materials and methods for their production and use
US4808471A (en) * 1985-03-01 1989-02-28 Minnesota Mining And Manufacturing Company Flat transparent top coat for retroreflective sheeting
US4950525A (en) * 1983-04-11 1990-08-21 Minnesota Mining And Manufacturing Company Elastomeric retroreflective sheeting
US5175646A (en) * 1990-05-24 1992-12-29 Eden Elizabeth A Reflective roll-up signs
US5254390A (en) * 1990-11-15 1993-10-19 Minnesota Mining And Manufacturing Company Plano-convex base sheet for retroreflective articles and method for making same
WO1994024654A1 (en) * 1993-04-14 1994-10-27 Re-Mark-It (Holdings) Limited An erasable sign
US5442870A (en) * 1993-09-08 1995-08-22 Kochanowski; George E. Reflective sign
US5759671A (en) * 1994-12-16 1998-06-02 Nippon Carbide Kogyo Kabushiki Kaisha Ultraviolet luminescent retroreflective sheeting
US6110574A (en) * 1995-12-12 2000-08-29 Nippin Carribe Kogyo Kabushiki Kaisha Retroreflective sheeting
US6253477B1 (en) 1998-09-23 2001-07-03 Hallmark Technologies, Inc. Retro-reflective sign
CN102490510A (en) * 2011-12-01 2012-06-13 宁波长阳科技有限公司 Polyester reflective membrane for printing and preparation method thereof
WO2014189751A1 (en) 2013-05-22 2014-11-27 Clearink Displays Llc Method and apparatus for improved color filter saturation
EP3141935A1 (en) * 2015-09-11 2017-03-15 Daehan A&C Co., Ltd. Open-type color reflective sheet and method of manufacturing the same
US9612501B2 (en) 2013-09-30 2017-04-04 Clearink Displays, Inc. Method and apparatus for front-lit semi-retro-reflective display
US9740075B2 (en) 2013-09-10 2017-08-22 Clearink Displays, Inc. Method and system for perforated reflective film display device
US9746740B2 (en) 2013-05-13 2017-08-29 Clearink Displays, Inc. Registered reflective element for a brightness enhanced TIR display
US9897890B2 (en) 2014-10-07 2018-02-20 Clearink Displays, Inc. Reflective image display with threshold
US9939706B2 (en) 2013-03-26 2018-04-10 Clearink Displays, Inc. Displaced porous electrode for frustrating TIR and returning light through exit pupil
US9939707B2 (en) 2013-07-08 2018-04-10 Clearink Displays, Inc. TIR-modulated wide viewing angle display
US10261221B2 (en) 2015-12-06 2019-04-16 Clearink Displays, Inc. Corner reflector reflective image display
US10304394B2 (en) 2014-10-08 2019-05-28 Clearink Displays, Inc. Color filter registered reflective display
US10386547B2 (en) 2015-12-06 2019-08-20 Clearink Displays, Inc. Textured high refractive index surface for reflective image displays
US10386691B2 (en) 2015-06-24 2019-08-20 CLEARink Display, Inc. Method and apparatus for a dry particle totally internally reflective image display
US10705404B2 (en) 2013-07-08 2020-07-07 Concord (Hk) International Education Limited TIR-modulated wide viewing angle display

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US4664966A (en) * 1985-11-18 1987-05-12 Minnesota Mining And Manufacturing Company Enclosed-lens retroreflective sheeting having tough, weather-resistant, transparent cover film
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US4264665A (en) * 1977-09-28 1981-04-28 Loefberg Hans F Reflex device with marking behind cover layer
US4405676A (en) * 1981-05-13 1983-09-20 Minnesota Mining & Manufacturing Company Decorative ribbon or sheet material
US4544586A (en) * 1982-12-27 1985-10-01 General Electric Company Laminar structure of polyester
US4950525A (en) * 1983-04-11 1990-08-21 Minnesota Mining And Manufacturing Company Elastomeric retroreflective sheeting
US4609587A (en) * 1984-11-30 1986-09-02 Potters Industries, Inc. Retroreflective materials and use
US4756931A (en) * 1984-11-30 1988-07-12 Potters Industries, Inc. Retroreflective materials and methods for their production and use
US4808471A (en) * 1985-03-01 1989-02-28 Minnesota Mining And Manufacturing Company Flat transparent top coat for retroreflective sheeting
US4639235A (en) * 1985-03-08 1987-01-27 Ibe Rebecca C Attachable eye for dolls
US4663213A (en) * 1985-11-18 1987-05-05 Minnesota Mining And Manufacturing Company Transparent multi-layer cover film for retroreflective sheeting
US5175646A (en) * 1990-05-24 1992-12-29 Eden Elizabeth A Reflective roll-up signs
US5254390A (en) * 1990-11-15 1993-10-19 Minnesota Mining And Manufacturing Company Plano-convex base sheet for retroreflective articles and method for making same
AU650082B2 (en) * 1990-11-15 1994-06-09 Minnesota Mining And Manufacturing Company Plano-convex base sheet for retroreflective articles and method for making same
US5468540A (en) * 1990-11-15 1995-11-21 Minnesota Mining And Manufacturing Company Retroreflective article comprising a transparent base sheet and nacreous pigment coating, method for making such a base sheet, and method for making a forming master
US5670096A (en) * 1990-11-15 1997-09-23 Minnesota Mining And Manufacturing Company Retroreflective article comprising a transparent base sheet and nacreous pigment coating, method for making such a base sheet, and method for making a forming master
WO1994024654A1 (en) * 1993-04-14 1994-10-27 Re-Mark-It (Holdings) Limited An erasable sign
US5442870A (en) * 1993-09-08 1995-08-22 Kochanowski; George E. Reflective sign
US5759671A (en) * 1994-12-16 1998-06-02 Nippon Carbide Kogyo Kabushiki Kaisha Ultraviolet luminescent retroreflective sheeting
US6110574A (en) * 1995-12-12 2000-08-29 Nippin Carribe Kogyo Kabushiki Kaisha Retroreflective sheeting
US6253477B1 (en) 1998-09-23 2001-07-03 Hallmark Technologies, Inc. Retro-reflective sign
CN102490510A (en) * 2011-12-01 2012-06-13 宁波长阳科技有限公司 Polyester reflective membrane for printing and preparation method thereof
US9939706B2 (en) 2013-03-26 2018-04-10 Clearink Displays, Inc. Displaced porous electrode for frustrating TIR and returning light through exit pupil
US9746740B2 (en) 2013-05-13 2017-08-29 Clearink Displays, Inc. Registered reflective element for a brightness enhanced TIR display
EP2999989A4 (en) * 2013-05-22 2017-01-04 Clearink Displays, Inc. Method and apparatus for improved color filter saturation
US10203436B2 (en) 2013-05-22 2019-02-12 Clearink Displays, Inc. Method and apparatus for improved color filter saturation
CN105264422A (en) * 2013-05-22 2016-01-20 清墨显示有限责任公司 Method and apparatus for improved color filter saturation
WO2014189751A1 (en) 2013-05-22 2014-11-27 Clearink Displays Llc Method and apparatus for improved color filter saturation
US10705404B2 (en) 2013-07-08 2020-07-07 Concord (Hk) International Education Limited TIR-modulated wide viewing angle display
US9939707B2 (en) 2013-07-08 2018-04-10 Clearink Displays, Inc. TIR-modulated wide viewing angle display
US9740075B2 (en) 2013-09-10 2017-08-22 Clearink Displays, Inc. Method and system for perforated reflective film display device
US9612501B2 (en) 2013-09-30 2017-04-04 Clearink Displays, Inc. Method and apparatus for front-lit semi-retro-reflective display
US9897890B2 (en) 2014-10-07 2018-02-20 Clearink Displays, Inc. Reflective image display with threshold
US10304394B2 (en) 2014-10-08 2019-05-28 Clearink Displays, Inc. Color filter registered reflective display
US10386691B2 (en) 2015-06-24 2019-08-20 CLEARink Display, Inc. Method and apparatus for a dry particle totally internally reflective image display
CN106526729A (en) * 2015-09-11 2017-03-22 大韩艾恩希有限公司 Open-type color reflective sheet and method of manufacturing the same
CN106526729B (en) * 2015-09-11 2018-05-04 大韩艾恩希有限公司 A kind of preparation method of style of opening colour reflective piece
US9726793B2 (en) 2015-09-11 2017-08-08 Daehan A&C Co., Ltd. Open-type color reflective sheet and method of manufacturing the same
EP3141935A1 (en) * 2015-09-11 2017-03-15 Daehan A&C Co., Ltd. Open-type color reflective sheet and method of manufacturing the same
US10261221B2 (en) 2015-12-06 2019-04-16 Clearink Displays, Inc. Corner reflector reflective image display
US10386547B2 (en) 2015-12-06 2019-08-20 Clearink Displays, Inc. Textured high refractive index surface for reflective image displays

Also Published As

Publication number Publication date
ZA755962B (en) 1976-08-25
FR2334123A1 (en) 1977-07-01
AT355460B (en) 1980-03-10
DK152797C (en) 1988-12-05
ATA732275A (en) 1979-07-15
LU73425A1 (en) 1976-04-13
NL174405C (en) 1984-06-01
DK411975A (en) 1976-12-07
JPS562921B2 (en) 1981-01-22
DE2542583C2 (en) 1982-02-25
FR2334123B1 (en) 1978-05-12
GB1470286A (en) 1977-04-14
SE7510412L (en) 1976-12-07
DE2542583A1 (en) 1977-05-05
DK152797B (en) 1988-05-16
IT1047575B (en) 1980-10-20
BE833604A (en) 1976-01-16
JPS51144198A (en) 1976-12-10
SE412960B (en) 1980-03-24
NL7511508A (en) 1976-12-08

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